html, body { height: 100%; }
body {
  margin: 0;
  background: #0b1220;
  color: #e5e7eb;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "PingFang SC", "Microsoft Yahei", sans-serif;
}
canvas { display: block; }
.hud {
  position: fixed;
  top: 10px; left: 10px; right: 10px;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 14px; z-index: 10; pointer-events: none;
}
.hud .left, .hud .right { display: flex; gap: 12px; align-items: center; }
.hud .right div { background: rgba(0,0,0,0.35); padding: 6px 10px; border-radius: 8px; }

/* 开始界面样式 */
#start-screen {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0,0,0,0.55);
  z-index: 9999;
}
#start-screen .panel {
  background: #111827;
  border: 1px solid rgba(255,255,255,0.5);
  border-radius: 12px;
  padding: 24px 28px;
  min-width: 420px;
}
#start-screen .panel h2 { margin: 0 0 8px; }
#start-screen .panel p { margin: 0 0 16px; color: #cbd5e1; }
#start-screen .buttons { display: flex; flex-direction: column; gap: 10px; }
#start-screen button {
  pointer-events: auto;
  background: #2563eb;
  color: white;
  border: none;
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 16px;
  cursor: pointer;
}
#start-screen button:hover { background: #1d4ed8; }